The cyclodepsipeptide derivative of this invention, represented by the following general formula (I), is known to be a compound having high vermicidal activity and finds application as an anthelmintic in animals and man. In the conventional synthesis of such cyclodepsipeptides, the cyclization reaction involved is invariably carried out in the manner of amide bond formation to construct a cyclic structure (WO 93/19053, Kokai Tokkyo Koho H5-320148, EP-626375, EP-626376).
For example, a cyclization process using the following route is known (WO 93/19053).
Conventional Route: ##STR2##